Multi-Protocol Label Switching (MPLS)-Transport Protocol (TP)) is a network protocol for transport of client traffic that encapsulates the independent of client network protocol. An MPLS-TP network can be formed by a label switching routers (LSRs), each connected by a data plane link to one or more immediate neighbor LSRs, or to one among a plurality of label edge routers (LERs) located at various edges of the MPLS-TP network.
MPLS-TP is a profile of MPLS, comprising a subset of the MPLS protocol suite, e.g., certain MPLS functions disabled or omitted, with certain additions or extensions, generally to meet transport network requirements. As known to persons of ordinary skill in the art, MPLS-TP can be carried over physical transport technologies, for example, SONET/SDH, OTN/WDM, and Gigabit Ethernet.
In conventional technique MPLS-TP networks, the term “bi-directional associated tunnel” refers to an arrangement of two uni-directional tunnels, extending opposite one another between the same end-points within the network. The end-points may be two label switching routers (LSRs) at respective “edges” of MPLS-TP network. Specifications and definitions for MPLS-TP networks are published in, for example, Internet Engineering Task Force (IETF) Request for Comment (RFC) document RFC 5654, and elsewhere. The two opposite direction tunnels can be associated with one another by an association binding established in the provisioning of the bi-directional associated tunnel. The provisioning of the bi-directional associated tunnel can be performed by network control signaling that uses a dynamic signaling protocol such as, for example, an extension of Resource Reservation Protocol-Traffic Engineering (RSVP-TE) signaling. The term “dynamic,” in this context, generally refers to a control signaling protocol having low enough latency and sufficient bandwidth to provide on-the-fly changing of network parameters, to quickly adapt to client application-specific transport requirements. Provisioning of a bi-directional associated tunnel through control signaling according to dynamic signaling protocol can enable a verifying of the association binding.
Conventional techniques exist for provisioning of bi-directional associated tunnel tunnels in MPLS-TP networks using a static network control signaling protocol not within the GMPLS-RSVP-TE signaling control plane. The conventional techniques include end-point association, at both end-points, of the forward and reverse member LSPs. However, CLI based end-point association of a forward LSP and a reverse LSP is only known to each end-point locally. Neither of the two end-points can verify that the two LPS(s) are also associated at the other (i.e., remote) end-point. This inability to verify can be associated with fault conditions such as traffic black hole due, for example, to miss-configuration or missing configuration.